FIELD OF THE INVENTION
[0001] This invention relates to a silver halide photographic material and more particularly
to a silver halide photographic material capable of being handled under substantially
bright surroundings, e.g., in a normally lit room. (hereafter simply "a bright room").
BACKGROUND OF THE INVENTION
[0002] In a step of producing printing plates, recently, photographic light-sensitive materials
which can be handled in bright room in spite of using silver halide as the photographic
element are being developed which meet the requirement of performing a contact exposure
(so-called contact work) using a relatively low-speed light-sensitive material. Such
results are attained by exposing a light-sensitive material having greatly reduced
light sensitivity (about 1/10⁴ to 1/10⁵ that of ordinary sensitivity) to visible light
to a light source containing a high proportion of ultraviolet (e.g., a very high pressure
mercury lamp, a metal halide lamp, etc.,) under a safe light containing substantially
no ultraviolet.
[0003] On the other hand, in contact work, simple one sheet contact work (i.e., a nega/posi
image conversion is performed contact-exposing one image-exposed and developed photographic
film as an original and a light-sensitive material for contact work) and high-level
image-conversion work for making so-called white lettering, on a solid background
or a white-on-black headline are performed. The term "white lettering on a solid background"
means uninked portions of letters, marks, etc., in a dot-like inked pattern on paper
(dotted portion) or a wholly inked portion on paper (called "a solid black portion")
in printed material.
[0004] The manner of making white lettering on a black background in producing printing
plates will now be explained more practically.
[0005] As shown in Fig. l, a base l has adhered thereto a developed film 2 (line image)
having line positive images such as letters, marks, etc., is disposed on a transparent
or translucent base 3 (usually a polyethylene terephthalate film a few hundred µm
in thickness) which has adhered thereto a developed film (dot image original) which
has dot images. The dot image portion of the assembly is brought into intimate contact
with an emulsion surface of a light-sensitive material 5 for contact work followed
by light-exposure development to form white line image portions in the dot images.
[0006] An important point in the above procedure is that the dot image and line image must
be subjected to a nega-posi image conversion according to the dot area and the line
width, respectively. For example, a dot image having 50% black area must be correctly
converted into a dot image having a 50% white area and a line image having a black
line width of 50 µm must be correctly converted into a line image having a white line
width of 50 µm. However, as is clear from Fig. l, the dot image is exposed to the
light sensitive material for contact work in a state of intimate contact with the
emulsion surface of the light-sensitive material, while the line image is exposed
to the light-sensitive material through the dot image original 4 (usually having a
thickness of about l10 µm) and the base 3 therefor (usually having a thickness of
100 µm). In other words, the line image is exposed to the light-sensitive material
for contact work as a vague line image since exposure is carried out through transparent
or translucent spacers a few hundred µm thick. Accordingly, when conventional exposure
amount (the exposure amount to faithfully nega/posi convert a dot image) is applied,
the white line width of the line image becomes narrow by the influence of the diffused
exposure. On the other hand, when the exposure amount is reduced to reducing the influence
of the exposure to faithfully perform the nega-posi conversion of the line width
of the line image, the dot area is reduced due to the insufficiency of the exposure.
[0007] Further, an attempt to reducing the influence of the exposure through multiple substrates
to improve the quality of white lettering on solid background encounters the problem
that adhering traces of a tape used to fix the line image or dot imates on the base
and pin hole marks are liable to appear.
[0008] Also, a silver halide light-sensitive material for contact work in a bright room
is liable to form pin holes due to dust, etc., when it is exposed to ultraviolet rays
as compared with conventional light-sensitive materials for contact work in a dark
room.
[0009] Means for preventing a reduction of the quality of white lettering on a black background
and a reduction in image quality due to the formation of adhering tape traces and
pin hole marks have scarcely been reported until now since the above-described procedures
are different from conventional improvements in photographic characteristics (e.g.,
sensitization, improvement of dot image quality, increasing the contrast of a characteristic
curve, etc.), directed to improving a light-sensitive materials for making printing
plates.
SUMMARY OF THE INVENTION
[0010] The major object of this invention is, therefore, to provide a silver halide photographic
material for a bright room, which can be handled under a bright safe light (in a bright
room) including visible rays which provides excellent white letter-quality on a black
background as compared to conventional light-sensitive materials for a bright room
with less adherence of tape trace and less pin hole marks. The term "bright room"
means a surroundings wherein a room light containing visible rays under which a photosensitive
material does not cause fog is used.
[0011] The above-described object of this invention is attained as set forth below.
[0012] That is, the invention relates to a silver halide photographic material for a bright
room comprising a support having thereon at least one silver halide emulsion layer
containing silver chloride grains or silver chlorobromide grains containing at least
80 mol% silver chloride, at least one of said silver halide emulsion layer on other
hydrophilic colloid layer(s) containing a yellow dye which renders the silver halide
photographic material substantially insensitive to visible light having a wavelength
of 420 n.m. or more and a ultraviolet absorbent in an amount capable of reducing the
specific sensitivity of the silver halide emulsion at 360 n.m. to 1/2 or less than
1/2 thereof, preferably from 1/2 to 1/100, more preferably from 1/2 to 1/20 to the
specific sensitivity of an otherwise identical silver halide emulsion free of the
ultraviolet absorbent, and the γ value of the silver halide photographic material
being at least 10, preferably from 10 to 50 more preferably from 10 to 30.
[0013] The term "substantially insensitive to visible light" means that a silver halide
photographic material has 0.02 or less, preferably 0.01 or less, of fog when it is
exposed to 200 lux of fading preventing fluorescent lamp made by Toshiba Corporation
through a sharp cut filter SC-42 (a filter with 50% transmittance at 420 n.m., absorbing
light of shorter wavelengths than 420 n.m. and transmitting light of longer wavelengths,
made by Fuji Photo Film Co., Ltd.) for 60 minutes, and developed with a developer
of Example l of the present specification.
[0014] The term "specific sensitivity of silver halide emulsion" is defined in
The Theory of the Photographic Process, 4th edition page 39 (published by Macmillan Co., l977).
BRIEF DESCRIPTION OF THE DRAWING
[0015] The figure is an enlarged view illustrating a procedure of making white letterings
on a black background in photographically making a printing plate.
DETAILED DESCRIPTION OF THE INVENTION
[0016] The silver halide in the silver halide photographic material of this invention is
silver chloride or silver chlorobromide containing at least 80 mol% and preferably
at least 90 mol% silver chloride.
[0017] The silver halide emulsion for use in this invention may be or may not be chemically
sensitized. In the case of applying chemical sensitization, conventional chamical
sensitization can be used such as sulfur sensitization, reduction sensitization and
noble metal sensitization can be used individually or as a combination thereof. Of
these chemical sensitization methods, sulfur sensitization is preferred.
[0018] For sulfur sensitizer, one can use a sulfur compound contained in gelatin and other
various sulfur compounds such as thiosulfates, thioureas, rhodanins, etc. Specific
examples of sulfur sensitizers are given in U.S. Patents 1,574,944, 2,278,947, 2,410,689,
2,728,668, 3,501,313, 3,656,952, etc.
[0019] A typical noble metal sensitization is a gold sensitization using a gold complex
salt. Other noble metal sensitization methods include using complex salts of, for
example, platinum, palladium, rhodium, etc., and these can be, as a matter of course,
employed. Examples of noble metal sensitization are given in U.S. Patent 2,448,060,
British Patent 618,061, etc.
[0020] As reduction sensitizers, a stannous salt, an amine, formamidines sulfinic acid,
a silane compound, etc., can be used. Examples thereof are given in U.S. Patents 2,487,850,
2,518,698, 2,983,609, 2,983,610, 2,694,637, etc.
[0021] The mean grain size of the silver halide grains for use in this invention is preferably
less than 0.5 µm more preferably 0.5 µm to 0.05 µm, most preferably 0.3 µm to 0.05
µm. The term "mean grain size" is conventionally used in the silver halide photographic
arts and will be easily understood by one skilled in the art. When a silver halide
grain is a sphere or a grain similar to a sphere, grain size means the diameter of
the grain. When a silver halide grain is cubic, the grain size is (the long side length
x
) and is the algebraic average or geometarical average based on the mean grain projected
area. Details of the method of obtaining the mean grain size are given, for example,
in C.E. Mees and T.H. James,
The Theory of the Photographic Process, 3rd edition, pages 36-43 (published by Macmillan Co., 1966).
[0022] There is no particular restriction on the form of the silver halide grains for use
in this invention. That is, the form of the silver halide grains may be tabular, spherical,
regular-cubic, regular-octahedral, etc. It is preferred, however, that the grain size
distribution be narrow and in particular, a mono-dispersed silver halide emulsion
wherein 90%, preferably 95%, of all grains are in a grain size range of ± 40% of the
mean grain size is preferred.
[0023] As methods for reacting a soluble silver salt and a soluble halide to prepare silver
halide grains for use in this invention conventional methods such as a single jet
method, a double jet method, or a combination thereof can be used.
[0024] A conventional back mixing method (or back jet method) for forming silver halide
grains in the presence of excessive silver ions can also be used.
[0025] As one conventional double jet method, a controlled double jet method involving maintaining
a constant pAg in the liquid phase for forming silver halide grains can be used. According
to this method, a silver halide emulsion containing silver halide grains having a
regular crystal form and an almost unirom grain size can be obtained.
[0026] The formation of the silver halide grains is preferably performed under acidic conditions.
According to our experiments, we found that the effect of the present invention is
reduced when the silver halide grains are formed under neutral or alkaline conditions.
The pH range for forming the silver halide grains preferably is at most 6, more preferably
6 to 1, most preferably 5 to 1.
[0027] Two or more silver halide emulsion layers may be formed which include the dye and
absorbent per the present invention, but usually one emulsion layer is enough. The
coating amount of silver (silver coverage) of the silver halide emulsion is preferably
in the range of 1 g/m² to 8 g/m².
[0028] Per the present invention, to improve the ease handling a silver halide photographic
material in a bright room, a yellow dye which renders the silver halide photographic
material substantially insensitive to visible light of 420 n.m. or more in wavelength.
As the yellow dye, a dye having a peak in the range of 420 to 550 n.m., preferably
in the range of 420 to 500 n.m. can be used.
[0029] There is no particular restriction on the chemical structure of the yellow dye used
and oxonol dyes, hemioxonol dyes, merocyanine dyes, cyanine dyes, azo dyes, etc.,
can be used and of these dyes, water-soluble dyes are advantageous in the sense of
preventing the formation of any color residue after processing.
[0030] Specific examples of useful yellow dyes are the pyrozolooxonol dyes described in
U.S. Patent 2,274,782, diarylazo dyes described in U.S. Patent 2,956,879, the styryl
dyes and butadienyl dyes described in U.S. Patents 3,423,207 and 3,384,487, the merocyanine
dyes described in U.S. Patent 2,527,583, the merocyanine dyes and oxonol dyes described
in U.S. Patents 3,486,897, 3,652,284, and 3,718,472, the enaminohemioxonol dyes described
in U.S. Patent 3,976,661, the arylidene dyes described in Japanese Patent Application
(OPI) Nos. 3623/76, 20,822/77 (the term "OPI" as used herein means an "unexamined
published Japanese patent application"), Japanese Patent Application Nos. 54,883/85,
21,306/85, 117,456/85, and 54,883/85, and the dyes described in British Patent 584,609
and 1,177,429 and in Japanese Patent Application (OPI) Nos. 85130/73, 99620/84, 114,420/84
and U.S. Patents 2,533,472, 3,148,187, 3,177,078, 3,247,127, 3,540,887, 3,575,704,
and 3,653,905.
[0032] Per the present invention, a yellow dye is added so that the silver halide photographic
material will not exhibit substantial sensitivity to visible light of a wavelength
of 420 n.m. or longer than 420 n.m. The amount of the yellow dye added is such that
the absorbance at a 420 n.m. wavelength is at least 0.2, more preferably at least
0.4, most preferably 0.4 to 3.0. The amount thereof depends upon the molar extinction
co-efficient of the dye i.e., as a dye has a large value of molar extinction co-efficient,
the required amount of the dye to provide the same value of molar extinction coefficient
is small. The amount thereof usually in the range of 10⁻³ g/m² to 1 g/m².
[0033] The yellow dye per the present invention can be present in the silver halide emulsion
layer, a protective layer for the emulsion layer, an interlayer, etc., of the silver
halide photographic material of this invention.
[0034] Per the present invention, an ultraviolet absorbent is used in an amount sufficient
to reduce the specific sensitivity of the silver halide emulsion below 1/2 thereof
to improve the quality of white lettering on a black background and to reduce the
formation of adhering tape traces and pin hole marks. As the ultraviolet absorbent,
an ultraviolet absorbent having a peak absorbance in the range of 300 to 400 n.m.,
more preferably 300 to 380 n.m., can be used. The "peak absorbence" is defined by
a wavelength corresponding to a maximum absorbence of a dye containing-or absorbent
containing-gelatin layer, on a transparent base which is obtained using spectrophotometer.
[0035] Examples of ultraviolet absorbents for use in the present invention include aryl
group-substituted benzotriazole compounds, 4-triazolidone compounds, benzophenone
compounds, cinnamic acid ester compounds, butadiene compounds, benzoxazole compounds
and ultraviolet absorptive polymers.
[0036] Specific examples of ultraviolet absorbents for use in the present invention are
described in U.S. Patents 3,533,794, 3,314,794, 3,352,681, Japanese Patent Application
(OPI) No. 2784/71, U.S. Patents 3,705,805, 3,707,375, 4,045,229, 3,700,455, 3,499,762,
West German Patent Publication No. 1,547,863, etc.
[0037] The ultraviolet absorbent used in the present invention has a peak absorbence in
the range of 300 to 400 n.m., and the yellow dye used in the present invention has
a peak absorbence in the range of 420 n.m. or more. Therefore, the ultraviolet absorbent
reduces the specific sensitivity of the silver halide emulsion below 1/2 thereof to
improve a stability to ultraviolet light, and the yellow dye improves a stability
to light having wavelength of 420 n.m. or more.
[0038] Accordingly, it is preferable that the photo- sensitive material is treated under
a light containing visible light of 420 n.m. or more and exposure is carried out within
a wavelength range of 360 to 420 n.m.
[0040] In the present invention, the ultraviolet absorbent is added in an amount such that
the specific sensitivity of the silver halide emulsion at 360 n.m. is reduced to below
1/2 the specific sensitivity of the ultraviolet absorbent is absent and the amount
added is such that the absorbance at 360 n.m. becomes at least 0.3, preferably at
least 0.4.
[0041] The addition amount also depends upon the molar extinction coefficient of the ultraviolet
absorbent but is usually in the range of 10⁻³ g/m² to 1 g/m².
[0042] The ultraviolet absorbent can be incorporated in the silver halide emulsion layer,
a surface protective layer, an interlayer, etc.
[0043] The ultraviolet absorbent can be added to a coating composition of a light-insensitive
hydrophilic colloid layer of the silver halide photographic material as a solution
in an appropriate solvent such as water, an alcohol (e.g., methanol, ethanol, propanol,
etc.), acetone, methyl cellosolve, etc., or a mixture thereof.
[0044] The ultraviolet absorbents and yellow dyes may be used singly or as a mixture thereof,
respectively.
[0045] Per the present invention, the ultraviolet absorbent may be present in a layer with
the above-described yellow dye or may be present in a layer different from the layer
containing the yellow dye.
[0046] To increase the γ value of the silver halide photographic material of this invention
is above 10, a member of different procedures can be used. For example, one can process
the silver halide photographic material containing a specific hydrazine derivative
as disclosed in U.S. Patents 4,166,742, 4,168,977, 4,221,857, 4,224,401, 4,243,739,
4,272,606, 4,311,781, etc., with a developer containing a sulfite preservative in
an amount of at least 0.15 mol/liter and at pH of 10.5 to 12.3 having good storage
stability, process the silver halide photographic material containing a tetrazolium
compound is disclosed in Japanese Patent Application (OPI) Nos. 18,317/77, 17,719/78
and 17,720/78 with a developer comprising p-aminophenol type developing agent and
dihydroxybenzene developing agent (PQ type developer) or a developer comprising l-phenyl-3-pyrazolidones
developing agent and dihydroxybenzene developing agent (PQ type developer), or process
the silver halide photographic material containing polyalkyleneoxide as disclosed
in Japanese Patent Application (OPI) No. 190943/83 with a developer containing dihydroxybenzenes
as a developing agent.
[0047] The γ value per the present invention is the value given by the following equation
when the exposure amount necessary for forming a blackened transmission density of
0.3 processed by each developer is defined as "A" and the exposure amount necessary
for giving a blackened transmission density of 3.0 is defined as "B";
γ = - (3.0 - 0.3)/(logA - logB)
[0048] Examples of compounds preferably used in the case of increasing the γ value of the
silver halide photographic material using a hydrazine derivative are compounds represented
by formula (III-1)
R₁ - NHNH - G - R₂ (III-1)
wherein R₁ represents an aliphatic or aromatic group;
or unsaturated heterocyclic group; R₂ represents a hydrogen atom, a substituted or
unsubstituted alkyl group, a substituted or unsubstituted aryl group; a substituted
or unsubstituted alkoxy group, or a substituted or unsubsti5tuted aryloxy group;
and G represents a carbonyl group, a sulfonyl group, a sulfoxy group, a phosphoryl
group, or an N-substituted or unsubstituted iminomethylene group, and include arylhydrazides
represented by formula (III-2), as described in U.S. Patent 4,478,928,
wherein Acyl is an acyl group, Ar is an aryl group, and R¹ʼ is a hydrogen atom or
a sulfinic acid radical substituent and R²ʼ is a sulfinic acid radical substituent
when R¹ʼ is hydrogen atom and hydrogen atom when R¹′ is a sulfinic acid radical.
[0049] In formula (I), suitable aliphatic groups represented by R₁ include those containing
from 1 to 30 carbon atoms, particularly preferably straight-chain, branched chain,
and cyclic alkyl groups containing from l to 20 carbon atoms. Herein, the branched-chain
alkyl groups may include those cyclized so as to form a saturated hetero ring containing
one or more hetero atoms therein such as a nitrogen atom, an oxygen atom, a sulfur
atom, a selenium atom, etc. Further, these alkyl groups may substituted with an aryl
group containing from 6 to 12 carbon atoms, an alkoxy group containing from l to 10
carbon atoms, a sulfoxy group containing from 1 to l0 carbon atoms, a sulfonamido
group containing from l to 10 carbon atoms, a carbonamido group containing from l
to 10 carbon atoms, and so on.
[0050] In formula (III-1), aromatic groups represented by R₁ include monocyclic and dicyclic
(conjugated) aryl groups.
[0051] The unsaturated heterocyclic groups represented by R₁ contain a nitrogen atom, an
oxygen atom, a sulfur atom, a selenium atom, etc. as a heteroatom and may be groups
formed by fusing together with a monocyclic or dicyclic aryl group.
[0052] Preferable examples of these aromatic groups represented by R₁ include phenyl, naphthyl,
pyridyl, pyrimidinyl, imidazolyl, pyrazolyl, quinolyl, isoquinolyl, benzimidazolyl,
thiazolyl, benzothiazolyl, and like groups. Of these groups, those containing a benzene
nucleus are more desirable.
[0053] A particularly preferred group as R₁ is a phenyl group and a naphthyl group.
[0054] An aryl group or a unsaturated heterocyclic group represented by R₁ may have one
or more substituent groups. Typical examples of such a substituent group include straight-chain,
branched-chain and cyclic alkyl groups (preferably containing from l to 20 carbon
atoms), aralkyl groups (an alkyl moiety of which preferably contains from l to 3 carbon
atoms, and an aryl moiety of which contains one or two rings), an alkoxy groups (preferably
containing from l to 20 carbon atoms), substituted amino groups (preferably having
an alkyl substituent containing from l to 20 carbon atoms), acylamino groups (preferably
containing from 2 to 30 carbon atoms), sulfonamido groups (preferably containing from
l to 30 carbon atoms), ureido groups (preferably containing from l to 30 carbon atoms),
thioureido groups thioamido groups, arylideneimino groups, heteroarylidene groups,
alkylideneimino groups, etc.
[0055] In formula (III-1), alkyl groups represented by R₂ preferably contain from l to 4
carbon atoms, and they may be substituted with a halogen atom, a cyano group, a carboxy
group, a sulfo group, an alkoxy group containing from 1 to 10 carbon atoms, a phenyl
group, etc.
[0056] Aryl groups represented by R₂ contain one or two (condensed) rings, e.g., those containing
a benzene ring. These aryl groups may be substituted with a halogen atom, an alkyl
group containing from l to 10 carbon atoms, a cyano group, a carboxyl group, a sulfo
group, etc.
[0057] Alkoxy groups represented by R₂ contain from l to carbon atoms, and may be substituted
with a halogen atom, an aryl group; etc.
[0058] Aryloxy groups represented by R₂ are preferably monocyclic. Substituent groups suitable
therefor are halogen atoms, etc.
[0059] Of groups represented by R₂, those preferred over others are hydrogen atom, an alkyl
group such as a methyl group, etc., an alkoxy group such as a methoxy group, an ethoxy
group, etc., and a substituted or unsubstituted aryl group such as a substituted or
unsubstituted phenyl group, etc., in the case where G represents a carbonyl group.
In particular, a hydrogen atom is preferred as R₂.
[0060] In the case G represents a sulfonyl group, R₂ is preferably an alkyl group such as
a methyl group, an ethyl group, etc.; a phenyl group; or a substituted aryl group
such as 4-methylphenyl group, etc., and particularly preferably is a methyl group.
[0061] In the case G represents a phosphoryl group, R₂ is preferably an alkoxy group such
as a methoxy group, an ethoxy group, a butoxy group, etc.; an unsubstituted aryloxy
group such as a phenoxy group, etc., or an aryl group such as a phenyl group, etc.,
and particularly preferably is a phenoxy group.
[0062] In the case G represents a sulfoxy group, preferred R₂ is a substituted alkyl group
such as a cyanobenzyl group, a methylthiobenzyl group or the like, while when G represents
an N-substituted or unsubstituted iminomethylene group, preferred R₂ groups are a
methyl group, an ethyl group, or a substituted or unsubstituted phenyl group.
[0063] Into R₁ or R₂ of formula (III-1) there may be introduced a ballast group as is commonly
used in immobile photographic additives such as a coupler. A ballast group as used
herein signifies a group containing not less than 8 carbon atoms preferably 8 to 20
carbon atoms which is relatively inert with respect to its influence on photographic
properties, and can be selected from among alkyl groups, containing from 8 to 30 carbon
atoms, alkoxy groups containing from 8 to 30 carbon atoms, phenyl group, alkylphenyl
groups containing from 8 to 30 carbon atoms, phenoxy group, alkylphenoxy groups containing
from 8 to 30 carbon atoms and the like.
[0064] Further, a group capable of increasing the adsorption to the surface of a silver
halide grain may be introduced into R₁ or R₂ of formula (III-1). As examples of such
adsorptive groups, mention may be made of those described in U.S. Patent 4,385,108,
such as thiourea groups, heterocyclic thioamido groups, mercaptoheterocyclic groups,
triazol groups, etc.
[0065] The most preferred group as G of formula (III-1) carbonyl group.
[0067] The hydrazine derivatives or arylhydrazides are well known compounds and prepared
according to the processes as described in Japanese Patent Application (OPI) Nos.
89738/81, 153336/81, 99635/82, 58137/82, 129436/82, 129433/82, 129434/82, 129435/82,
83028/85, 93433/85, 112034/85, 129746/85, 140338/85, 140339/85, 140340/85, 179734/85,
200250/85, etc.
[0068] It is most effective to add a hydrazine derivative as above described per the present
invention in an amount ranging from 1 × 10⁻⁶ to 5 × 10⁻² mole. Particularly from 1
× 10⁻⁵ to 2 × 10⁻² mole, per mole of silver halide.
[0069] In incorporating a hydrazine derivative which can be employed in the present invention
into a photographic light-sensitive material, the hydrazine derivative can be added
to a silver halide emulsion or a hydrophilic colloidal solution as an aqueous solution
when it is soluble in water or as a solution prepared by dissolving it in a water
miscible organic solvent, such as an alcohol (e.g., methanol, ethanol, etc.), esters
(e.g., ethyl acetate), ketones (e.g., acetone) or the like, when it is insoluble in
water.
[0070] The hydrazine derivatives may be added alone or as a mixture of two or more thereof.
[0071] A layer in which the hydrazine derivatives are to be incorporated may be either silver
halide emulsion layer or another hydrophilic colloid layer. Also, the hydrazine derivatives
may be incorporated in both silver halide emulsion layer and another hydrophilic colloid
layer.
[0072] In the case of increasing the γ value of the silver halide photographic material
above 10 by using a tetrazolium compound, the compounds described in Japanese Patent
Application (OPI) No. 18,317/77, 17,719/78, 17,720/78, etc., can be used. Typical
tetrazolium compounds which can be used for the purpose are represented by following
general formulae (IV) to (vI):
[0073] In the above formulae, R₁, R₃, R₄, R₅, R₈, R₉, R₁₀, and R₁₁ each represents an allyl
group, a phenyl group (e.g., a phenyl group, a tolyl group, a hydroxyphenyl a carboxyphenyl
group, an aminophenyl group, a mercaptophenyl group, etc.), a naphthyl group (e.g.,
an α-naphthyl group, β-naphthyl group, a hydroxynaphthyl group, a carboxynaphthyl
group, an aminonaphthyl group, etc.), or a heterocyclic group (e.g., a thiazolyl group,
a benzothiazolyl group, an oxazolyl group, a pyrimidinyl group, a pyridyl group, etc.),
and these groups each may be a group forming a metal chelate or a complex; R₂, R₆
and R₇ each represents an allyl group, a phenyl group, a naphthyl group, a heterocyclic
group, an alkyl group (e.g., a methyl group, an ethyl group, a propyl group, a butyl
group, a mercaptomethyl group, a mercaptoethyl group, etc.), a hydroxy group, a carboxy
group or a salt thereof, a carboxyalkyl group (e.g., a methoxycarbonyl group, an ethoxycarbonyl
group, etc.), an amino group, (e.g., an amino group, an ethylamino group, an anilino
group, etc.), a mercapto group, a nitro group, or a hydrogen atom; D represents a
divalent aromatic group; E represents an alkylene group, an arylene group, or an aralkylene
group; X represents an anion(preferably a chloride ion, a bromide ion, perchlorate
ion, etc.), and n represents 1 or 2; n is 1 when the compound of each general formula
forms an intramolecular salt.
[0074] Specific examples of the tetrazolium compound for use in this invention are illustrated
below but such is not intended to limit the compounds which can be used in this invention.
(1) 2-(Benzothiazol-2-yl)-3-phenyl-5-dodecyl-2H-tetrazolium-bromide.
(2) 2,3-Diphenyl-5-(4-t-octyloxyphenyl)-2H-tetrazoliumchloride.
(3) 2,3,5-Triphenyl-2H-tetrazolium.
(4) 2,3,5-Tri(p-carboxyethylphenyl)-2H-tetrazolium.
(5) 2-(Benzothiazol-2-yl)-3-phenyl-5-(o-chlorophenyl)-2H-tetrazolium.
(6) 2,3-Diphenyl-2H-tetrazolium.
(7) 2,3-Diphenyl-5-methyl-2H-tetrazolium.
(8) 3-(p-Hydroxyphenyl)-5-methyl-2-phenyl-2H-tetrazolium.
(9) 2,3-Diphenyl-5-ethyl-2H-tetrazolium.
(10) 2,3-Diphenyl-5-n-hexyl-2H-tetrazolium.
(11) 5-Cyano-2,3-diphenyl-2H-tetrazolium.
(12) 2-(Benzothiazol-2-yl)-5-phenyl-3-(4-tolyl)-2H-tetrazolium.
(13) 2-(Benzothiazol-2-yl)-5-(4-chlorophenyl)-3-(4-nitrophenyl)-2H-tetrazolium.
(14) 5-Ethoxycarbonyl-2,3-di(3-nitrophenyl)-2H-tetrazolium.
(15) 5-Acetyl-2,3-di(p-ethoxyphenyl)-2H-tetrazolium.
(16) 2,5-diphenyl-3-(p-tolyl)-2H-tetrazolium.
(17) 2,5-Diphenyl-3-(p-iodophenyl)-2H-tetrazolium.
(18) 2,3-Diphenyl-5-(p-diphenyl)-2H-tetrazolium.
(19) 5-(p-Bromophenyl)-2-phenyl-3-(2,4,6-trichlorophenyl)-2N-tetrazolium.
(20) 3-(p-Hydroxyphenyl)-5-(p-nitrophenyl-2-phenyl-2H-tetrazolium.
(21) 5-(3,4-Dimethoxyphenyl)-3-(2-ethoxyphenyl-2-(4-methoxyphenyl)-2H-tetrazolium.
(22) 5-(4-Cyanophenyl)-2,3-diphenyl-2H-tetrazolium.
(23) 3-(p-Actamidophenyl)-2,5-diphenyl-2H-tetrazolium.
(24) 5-Acetyl-2,3-diphenyl-2H-tetrazolium.
(25) 5-(Fluoro-2-yl)-2,3-diphenyl-2H-tetrazolium.
(26) 5-(Thien-2-yl)-2,3-diphenyl-2H-tetrazolium.
(27) 2,3-Diphenyl-5-(pyrido-4-yl)-2H-tetrazolium.
(28) 2,3-Diphenyl-5-(quinol-2-yl)-2H-tetrazolium.
(29) 2,3-Diphenyl-5-(benzoxazol-2-yl)-2H-tetrazolium.
(30) 2,3-Diphenyl-5-nitro-2H-tetrazolium.
(31) 2,2′,3,3′-Tetraphenyl-5,5′-1,4-butylene-di-(2H-tetrazolium).
(32) 2,2′, 3,3′-Tetraphenyl-5,5′-p-phenylene-di-(2H-tetrazolium).
(33) 2-(4,5-Dimethylthiazol-2-yl)-3,5-diphenyl-2H-tetrazolium.
(34) 3,5-Diphenyl-2-(triazin-2-yl)-2H-tetrazolium.
(35) 2-(Benzothiazol-2-yl)-3-(4-methoxyphenyl)-5-phenyl-2H-tetrazolium.
[0075] The above tetrazolium compounds are obtained by conventionally known methods.
[0076] When the tetrazolium compound is used in a non-diffusible form, the non-diffusible
compound obtained by reacting a diffusible compound in the above-illustrated compounds
and an anion is used.
[0077] As the anion moiety for use in such a case, there are higher molecular weight alkylbenzenesulfonic
acid anions such as a p-dodecylbenzenesulfonic acid anion, etc., higher molecular
weight alkylsulfuric acid ester anions such as a lauryl sulfate anion, etc., dialkyl
sulfosuccinate anions such as a di-2-ethylhexyl sulfosuccinate anion, etc., polyether
alcohol sulfuric acid ester anions such as a cetyl polyethenoxysulfate anion, higher
fatty acid anions such as a stearic acid anion, etc. and a polymer such as a polyacrylic
acid anion, etc., having an acid residue.
[0078] Also, the non-diffusible tetrazolium compound for use in this invention can be synthesized
by appropriately selecting an anion moiety and a cation moiety. The non-diffusible
tetrazolium compound can be prepared by separately dispersing the anion moiety and
a cation moiety, which are both soluble salts, each in a gelatin solution followed
by mixing them and dispersing the mixture in gelatin matrix or by previously synthesizing
crystals of the oxidizing agent, dissolving the crystals in a solvent (e.g., dimethyl
sulfoxide, etc.), and then dispersing the solution in gelatin matrix. For uniform
dispersion, the above-described mixture may be dispersed by emulsification using
ultrasonic waves or a high-pressure homogenizer.
[0079] In the case of the present invention, either a diffusible tetrazolium compound or
a non-diffusible tetrazolium compound can be used, but images of higher contrast can
be obtained using a non-diffusible tetrazolium compound. Accordingly, when requiring
particularly excellent dot performance, the use of a non-diffusible tetrazolium compound
is advantageous.
[0080] The tetrazolium compounds for use in this invention may be used solely or as a mixture
thereof.
[0081] Also, in this invention, the tetrazolium compound(s) may be added to a silver halide
emulsion layer or other hydrophilic colloid layer(s), or further may be added to both
types of layers.
[0082] It is preferred that the tetrazolium compound(s) for use in this invention be used
in the range of l × 10⁻³ to 5 × 10⁻² mol per mol of silver halide.
[0083] To reduce the sensitivity of the silver halide emulsion and improve ease of handling
the silver halide photographic material in a bright room, a water-soluble rhodium
salt can be used in this invention. Specific examples of such a water-soluble rhodium
salt are rhodium chloride, rhodium trichloride, rhodium ammonium chloride, etc. Further,
complex salts of the aforesaid salts, such as Na₃ [RhCℓ₆]·9H₂O, etc., can be used
in this invention.
[0084] The above-described rhodium salt may be added to the silver halide emulsion in any
period before finishing the lst ripening at the production of the emulsion but it
is particularly preferably added during the formation of the silver halide grains.
The addition amount of the rhodium salt is generally l × 10⁻⁷ mol to l × 10⁻⁴, preferably
l × 10⁻⁶ mol to 5 × 10⁻⁵ mol per mol of silver.
[0085] The photographic material of the present invention can contain a wide variety of
compounds for purposes of preventing fogging and stabilizing photographic characteristics
during production, storage or photographic processing. More specifically, azoles such
as benzothiazolium salts, nitroindazoles, nitrobenzimidazoles, chlorobenzimidazoles,
bromobenzimidazoles, mercaptothiazoles, mercaptobenzothiazoles, mercaptobenzimidazoles,
mercaptothiadiazoles, aminotriazoles, benzotriazoles, nitrobenzotriazoles, mercaptotetrazoles
(especially l-phenyl-5-mercaptotetrazole), etc.; mercaptopyrimidines; mercaptotriazines;
thioketo compounds such as oxazolinethione; azaindenes such as triazaindenes, tetraazaindenes
(especially (1,3,3a,7)tetrazaindenes substituted with a hydroxy group at the 4-position),
pentaazaindenes, etc., and many other compounds known as an antifoggant or a stabilizer,
such as benzenthiosulfonic acid, benzenesulfinic acids, benzensulfonic acid amides
and so on can be added to the photographic material of the present invention.
[0086] The photographic emulsion and light-insensitive hydrophilic colloids which constitute
the photographic material of the present invention may contain inorganic or organic
hardeners, if desired.
[0087] Examples of hardeners which can be used include chrome salts (e.g., chrome-alum,
chromium acetate, etc.), aldehydes (e.g., formaldehyde, glyoxal, glutaraldehyde, etc.),
N-methylol compounds (e.g., dimethylolurea, methylol dimethylhydantoin, etc.), dioxane
derivatives (e.g., 2,3-dihydroxydioxane, etc.), active vinyl compounds (e.g., 1,3,5
triacryloyl-hexahydro-s-triazine, bis(vinylsulfonyl) methyl ether, N,N′-methylenebis
{β-(vinylsulfonyl)propioneamide}, etc.), active halogen compounds (e.g., 2,4-dichloro-6-hydroxy-s-triazine,
etc.), mucohalogen acids (e.g., mucochloric acid, mucophenoxychloric acid, etc.),
isoxazoles, dialdehyde starch, and 2-chloro-6-hydroxytriazinyl-modified gelatin. These
hardeners can be used alone or as a combination thereof, and specific examples thereof
are described in U.S. Patents 1,870,354, 2,080,019, 2,726,162, 2,870,013, 2,983,611,
2,992,109, 3,047,394, 3,057,723, 3,103,437, 3,321,313, 3,325,287, 3,362,827, 3,539,644
and 3,543,292, British Patents 676,628, 825,544 and 1,270,578, German Patents 872,153
and 1,090,427, Japanese Patent Publication Nos. 7133/59 and 1872/71, etc.
[0088] The light-sensitive emulsion layers and/or light-insensitive hydrophilic colloid
layers of the present invention may contain surface active agents for various purposes,
such as coating aids, prevention of static charging improvement of slippability, emulsifying
dispersions, prevention of adhesion, and improving photographic characteristics.
[0089] Gelatin is employed to advantage as a binder or a protective colloid of photographic
emulsions per this invention. Hydrophilic colloids other than gelatin can also be
used. For instance, other colloids which can be used include proteins such as gelatin
derivatives, graft copolymers of gelatin and other high molecular weight polymers,
albumin, casein, etc.; sugar derivatives such as cellulose derivatives (e.g., hydroxyethyl
cellulose, carboxymethyl cellulose, cellulose sulfate, etc.), sodium alginate, starch
derivatives and the like; and various kinds of synthetic hydrophilic macromolecular
substances such as homo- or co-polymers including polyvinyl alcohol, polyvinyl alcohol
partial acetal, poly-N-vinylpyrrolidone, polyacrylic acid, polymethacrylic acid, polyacrylamide,
polyvinylimidazole, polyvinylpyrazole, etc.
[0090] Not only can lime-processed gelatin be used but also acid-processed gelatin may be
used. Further, hydrolysis products of gelatin and enzymatic degradation products of
gelatin can also be employed.
[0091] The photographic emulsions of the present invention can contain dispersions of water
insoluble or slightly water soluble synthetic polymers for the purpose of improving
dimensional stability and so on. Examples of such polymers include those containing
as constituent monomers an alkyl(metha)acrylate, an alkoxyalkyl(metha)acrylate, a
glycidyl(metha)acrylate, a (metha)acrylamide, a vinyl ester (e.g., vinyl acetate),
acrylonitrile, an olefin, a styrene and so on, individually or as a combination of
two or more thereof, or as a combination of one or more of the above-described monomers
with acrylic acid, methacrylic acid, an α,β-unsaturated dicarboxylic acid, a hydroxyalkyl(metha)acrylate,
a sulfoalkyl(metha)acrylate, styrenesulfonic acid, and so on. Specific examples of
polymers which can be used tor the above-described purpose are described, for example,
in U.S. Patents 2,376,005, 2,739,137, 2,853,457, 3,062,674, 3,411,911, 3,488,708,
3,525,620, 3,607,290, 3,635,715 and 3,645,740, and British Patents 1,186,699 and 1,307,373.
[0092] For obtaining photographic images of very high contrast (10 or more in γ value) using
the silver halide photographic material of this invention containing a hydrazine derivative
and/or a tetrazolium compound, a stable developer can be used without need for use
of a conventional "unstable" infectious developer (lithographic developer).
[0093] In other words, for the above-described silver halide photographic material, a developer
containing a sufficient amount (in particularly, at least 0.15 mol/liter, preferably,
0.15 to 1.2 mol/liter) of sulfite ion as a preservative. The pH of the developer is
at least 9.5, particularly 10.5 to 12.3 in the case of using a hydrazine derivative,
or is in the range of 9 to 12, particularly in the range of 10 to 11, in the case
of using a tetrazolium compound.
[0094] The developing agent used in a developer employed for processing the photographic
light-sensitive material of the present invention does not have any particular restrictions.
However, it is desirable for the developing agent to include a dihydroxybenzene(s)
since excellent half-tone quality is easy to obtain. In some cases, combinations of
dihydroxybenzenes and 1-phenyl-3-pyrazolidones, or combinations of dihydroxybenzenes
and p-aminophenols, can be employed as developing agent.
[0095] Developing agents of the dihydroxybenzene type used in the above processing include
hydroquinone, chlorohydroquinone, bromohydroquinone, isopropylhydroquinone, methylhydroquinone,
2,3-dichlorohydroquinone, 2,5-dichlorohydroquinone, 2,3-dibromohydroquinone, 2,5-dimethylhydroquinone
and the like. Of these hydroquinones, hydroquinone is especially useful.
[0096] Developing agents of the l-phenyl-3-pyrazolidone type which can be used in the above
processing include 1-phenyl-3-pyrazolidone, l-phenyl-4,4-dimethyl-3-pyrazolidone,
1-phenyl-4-methyl-4-hydroxymethyl-3-pyrazolidone, 1-phenyl-4,4-dihydroxymethyl-3-pyrazolidone,
1-phenyl-5-methyl-3-pyrazolidone, 1-p-aminophenyl-4,4-dim'ethyl-3-pyrazolidone, 1-p-tolyl-4,4-dimethyl-3-pyrazolidone
and the like.
[0097] Developing agents of the p-aminophenol type which can be used in the above processing
include N-methyl-p-aminophenol, p-aminophenol, N-(β-hydroxyethyl)-p-aminophenol,
N-(4-hydroxyphenyl)glycine, 2-methyl-p-aminophenol, p-benzylaminophenol, and the
like. Of these compounds, N-methyl-p-aminophenol is especially useful.
[0098] In general, the developing agent(s) is/are used in an amount ranging from 0.05 mol/l
to 0.8 mol/l. When combinations of dihydroxybenzenes with 1-phenyl-3-pyrazolidones
or p-aminophenols are employed, it is most effective to use the former in an amount
of 0.05 mol/l to 0.5 mol/l and the latter in an amount of 0.06 mol/l or less.
[0099] Preservatives of the sulfite type used in the processing of the photographic light-sensitive
material of the present invention include sodium sulfite, potassium sulfite, lithium
sulfite, ammonium sulfite, sodium bisulfite,potassium metabisulfite, an addition product
of an aldehyde and sodium bisulfite, etc. A preferred addition amount of sulfite is
0.4 mol/l or more, particularly 0.5 mol/l or more, and the upper limit thereof is
up to 2.5 mol/l.
[0100] Alkali agents used for pH adjustment include pH controlling agents and buffering
agents, such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium
carbonate, sodium tertiary phosphate, potassium tertiary phosphate, etc.
[0101] In addition to the above-described ingredients, additives such as a development inhibitor
(e.g., boric acid, borax, sodium bromide, potassium bromide, potassium iodide, etc.),
an organic solvent (e.g., ethylene glycol, diethylene glycol, triethylene glycol,
dimethyl formamide, methyl cellosolve, hexylene glycol, ethanol, methanol, etc.),
and an anti-foggant or an agent for preventing black spots such as black pepper (e.g.,
mercapto compounds such as l-phenyl-5-mercaptotetrazole, sodium 2-mercaptobenzimidazole-5-sulfonate,
etc., indazole compounds such as 5-nitroindazole, etc., benzotriazole compounds such
as 5-methylbenzotriazole, etc., and so on) may be contained in the developer.
[0102] Further, the developer may optionally contain a toning agent, a surface active agent,
a defoaming agent, a water softener, a hardener, an amino compound as described in
Japanese Patent Application (OPI) No. 106244/81, etc.
[0103] The following example is intended to illustrate this invention in detail but not
to limit it in any way.
Example 1
[0104] Two kinds of Emulsions A and B were prepared using the following Solutions I and
II by the methods shown below.
Solution I: 300 ml of water and 9 g of gelatin
Solution II: 100 g of silver nitrate and 400 ml of water
1) Emulsion A (Rhodium: 0.5 × 10⁻⁵ mol/mol-silver:
[0105] Solution IIIA: 37 g of sodium chloride, l mg (NH₄)₃RhCℓ₆ and 400 ml of water.
[0106] To Solution I maintained at 45°C were simultaneously added solution II and solution
IIIA at a constant speed to form a silver halide emulsion. After removing soluble
salts from the emulsion by a Conventional method, gelatin and a stabillizer, 6-methyl-4-hydroxy-1,3,3a,7-tetraazaindene,
were added to the emulsion. The mean grain size of the silver halide grains in the
silver halide emulsion thus formed was 0.20 µm and the amount of gelatin was 60 g
per kg of the amount of the silver halide emulsion.
2) Emulsion B (Rhodium 5 × 10⁻⁵ mol/mol-silver:
[0107] Solution IIIB: 37 g of sodium chloride, 10 mg of (NH₄)₃RhCℓ₆, and 400 ml of water.
[0108] Emulsion B was prepared in the same manner as Emulsion A using Solution IIIB in place
of Solution IIIA.
[0109] To each of the Emulsions thus prepared were added a hydrazine derivative, the yellow
dye of this invention and an ultraviolet absorbent in the amounts shown in Table 1
below and, after further adding thereto a dispersion of polyethyl acrylate and 2-hydroxy-4,6-dichloro1,3,5-triazine
sodium salt, each mixture was coated on a polyethylene terephthalate film at a silver
coverage of 3.5 g/m².
[0110] An aqueous gelatin solution was then coated on the silver halide emulsion layer as
a protective layer at a gelatin coverage of l g/m².
[0111] Each of the light-sensitive samples thus obtained was exposed to light through an
optical wedge using a P-607 Type Printer, made by Dainippon Screen Mfg. Co., Ltd.
developed for 20 sec. at 38°C with a developer having the composition shown below,
and then stopped, fixed, washed and dried. The quality of white lettering on the black
background and the suitability for use under a safe light were compared for these
samples subjected to the above-described development processing.
[0112] The results obtained are shown in Table 1.
[0113] In Table l;
1): Relative sensitivity is shown by the reciprocal of the exposure amount providing
a density of 1.5 with that of Sample 5 being defined as 100.
2): γ=(3.0 - 0.3)/-[log(a) - log(b)].
(a): Exposure amount giving a density of 0.3
(b): Exposure amount giving a density of 3.0.
3): White lettering on black background evaluated as follows. That is, as shown in
Japanese Patent application (OPI) No. 190,943/83, a film assembly formed by disposing
a base film, a film having a line positive image (line image original), a base film
and a film having a dot image (dot image original) in this order is intimately contacted
with each of the samples prepared above with the protective layer of the sample and
the dot image original in face-to-face relationship, an appropriate exposure is applied
thereto in such a manner that 50% dot area becomes 50% dot area on the film sample
and then the film is processed as described above. In this case, a sample capable
of reproducing a letter of 30 µm in width as the line image original is evaluated
as Rank 5, a sample which can reproduce only a letter of 150 µm or more in width is
evaluated as Rank l, and Rankings 4, 3, and 2 are formed between Rank 5 and Rank l,
Rank 2 represents a usable limit.
4) Tape adhering traces and pin hole marks were evaluated as follows.
The original for evaluating the quality of white lettering on a black background was
prepared by fixing a line image original or a dot image original on a film base using
an adhesive tape. The possibility of dust and dirt attaching to the surfaces of the
original or the photographic light-sensitive material also exists, of course. Accordingly,
when light exposure and processing are performed as in the case of evaluating the
quality of white lettering on a black background uing the aforesaid original and/or
photographic light-sensitive material, transparent portions such as tape adhering
traces and pin hole marks caused by dust and dirt form on portions which are light-exposed
and essentially must be blackened.
Two white portions such as the tape adhering traces and pin hole marks are evaluated
with a visual sense into 5 ranks (Rank l is the worst and Rank 5 is the best). Rank
3 is the usable limit.
5): Fog (1) after safe light irradiation.
Fog formed when each sample is developed after irradiation with a fading preventing
fluorescent lamp (FLR 40 SW-DL-X NU/M) made by Toshiba Corporation for 30 minutes
or 60 minutes under about 200 lux.
6): Fog (2) after safe light irradiation.
[0114] Fog formed when each sample is developed after irradiation with a fading preventing
fluorescent lamp (FLR 40) SW-DL-X NU/M) made by Toshiba Corporation using a sharp
cut filter SC-402 (a filter with 50% transmittance at 420 n.m., absorbing light of
shorter wavelengths than 420 n.m. and transmitting light of longer wavelengths for
60 minutes under about 200 lux.
[0115] From the results shown in Table 1, it can be seen that Sample 4 of thi invention
gave good quality white lettering on a black background and resulted in less tape
adhering traces and pin hole marks and was excellent as compared with comparison Samples
l, 2, 3, and 5. On comparing Sample l with Samples 2 and 3, it can be seen that yellow
Dye (I - 1) is effective to improve the ability to be handled under a safe light and
Ultraviolet Absorbent (II - 20) is effective to improve the quality of the white lettering
on a background and to prevent the formation of tape adhering traces and pin hole
marks.
[0116] Also, it can be seen that when a sharp cut filter SC-42 is applied to the fading
preventing fluorescent lamp, the safe light safety of Sample 4 per this invention
was further improved.
[0117] While the invention has been described in detail and with reference to specific embodiments
thereof, it will be apparent to one skilled in the art that various changes and modification
can be made therein without departing from the spirit and scope thereof.